Conventionally, there has been a tactile sensation producing apparatus that includes a display means, a contact detecting means that detects a contact state of a user's manipulation region on the display means, and a tactile vibration generating means that generates tactile vibration that gives a predetermined tactile sensation to the user's manipulation region contacting the display means (for example, see Patent Document 1).
The tactile sensation producing apparatus further includes a vibration waveform data generating means that generates waveform data for generating the tactile vibration based on a detected result of the contact detecting means. Also, the tactile sensation producing apparatus further includes an ultrasound modulating means that performs a modulating process on the waveform data, generated by the vibration waveform data generating means, by utilizing ultrasound as a carrier wave and outputs an ultrasound modulation signal generated by the modulating process to the tactile vibration generating means as a signal for generating the tactile vibration.
Also, the ultrasound modulating means performs either a frequency modulation or a phase modulation. Also, the ultrasound modulating means further performs an amplitude modulation.
However, an ultrasound frequency used in the conventional tactile sensation producing apparatus may be any frequency as long as the frequency is higher than that of an audible frequency (approximately 20 kHz). No specific setting is made for the ultrasound frequency. Accordingly, there is a possibility that the tactile sensation producing apparatus does not provide a favorable tactile sensation.